• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1694-1697
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• 2010

지능형 빌딩 시스템은 빌딩을 운영하는 다양한 단위시스템 정보를 통합하여 빌딩 거주자에게 쾌적하고, 안전한 생활을 할 수 있도록 운영하는 시스템을 말한다. 하드웨어적인 방법은 단위시스템에 비례하게 비용이 증가하는 단점이 있다. 소프트웨어적인 방법은 하나의 서버에서 정보를 수집하기 때문에 단위시스템에 통신량 증가로 인한 오류가 발생하면 전체 시스템에 영향을 미치는 단점을 가지고 있다. 본 논문에서는 소프트웨어적인 방법의 단점을 개선하기 위해서 부하 및 오류를 격리화할 수 있는 가상화를 이용하여 통합 관리 시스템과 인터페이스 관리 시스템으로 운영한다. 시스템의 구조는 통합 관리 모듈, 가상 관리 모듈, 구성 관리 모듈, 그리고 단위시스템 관리 모듈로 분리되며 제안 시스템을 사용함으로써 인터페이스 관리 시스템에서 발생하는 오류 및 부하로 인한 전체 시스템 오류를 축소시킬 수 있다.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.51-59
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• 2009

This study is based on field data obtained from rock grouting such as RQD value, Unit cement grout volume, Lugeon value(Lu), and Maximum grout pressure in four different dam sites. The relationship were analyzed and compared as follow. The cut-off effect after rock grouting in dam-foundation which are mostly consist of metamorphic rock is better than that of Sedimentary rock. And the impermeable effect after consolidation grouting is more efficiency than the impermeable effect after curtain grouting. The unit cement grout volume are increased as RQD value is higher in rock mass. But there is no relationship between RQD value and Lugeon value. In the sedimentary rock, which is more permeable than metamorphic rock, Lugeon value (Lu) is a linear function (Lu=0.22Vc) of unit cement grout volume (Vc). Cut-off effect of curtain grouting is less influential at each near holes which are already grouted than that of consolidation grouting. And the behavior characteristics of Lugeon value vs. the unit cement grout volume as the order of installations are almost the same.

• School Mathematics
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• v.18 no.4
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• pp.819-838
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• 2016

This research analyzed proportional reasoning abilities of the 5th grade students who learned only the basis of ratio and rate and 6th grade students who also learned proportion and cross product strategy. Data were collected through the proportional reasoning tests and the interviews, and then the achievement of the students and their proportional reasoning strategies were analyzed. In the light of such analytical results, the conclusions are as follows. Firstly, there is not much difference between 5th and 6th grade students in the achievement scores. Secondly, both 5th and 6th graders are less familiar with the geometric, qualitative and comparisons tasks than the other tasks. Thirdly, not only 5th graders but also 6th graders used informal strategies much more than the formal strategy. Fourthly, some students can't come up with other strategies than the cross product strategy. Finally, many students have difficulties in discerning proportional situation and non-proportional situations. This study provided suggestions for improving teaching proportional reasoning in elementary schools in Korea as follows: focusing on letting students use their informal strategies fluently in geometric, qualitative, and comparisons tasks as well as algebraic, quantitative, and missing value tasks focusing on the concept of ratio and proportion instead of enforcing the formal strategy.

• Journal of Elementary Mathematics Education in Korea
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• v.19 no.4
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• pp.457-484
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• 2015

This study aims to investigate an approach to teach proportional reasoning in elementary mathematics class by analyzing the proportional strategies the students use to solve the proportional reasoning tasks and their percentages of correct answers. For this research 174 sixth graders are examined. The instrument test consists of various questions types in reference to the previous study; the proportional reasoning tasks are divided into algebraic-geometric, quantitative-qualitative and missing value-comparisons tasks. Comparing the percentages of correct answers according to the task types, the algebraic tasks are higher than the geometric tasks, quantitative tasks are higher than the qualitative tasks, and missing value tasks are higher than the comparisons tasks. As to the strategies that students employed, the percentage of using the informal strategy such as factor strategy and unit rate strategy is relatively higher than that of using the formal strategy, even after learning the cross product strategy. As an insightful approach for teaching proportional reasoning, based on the study results, it is suggested to teach the informal strategy explicitly instead of the informal strategy, reinforce the qualitative reasoning while combining the qualitative with the quantitative reasoning, and balance the various task types in the mathematics classroom.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1749-1755
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• 2014

Technique for analyzing a pile installed by vibrohammer was developed and parametric studies were executed in order to evaluate reliability of the developed technique. Comparing the accelerations obtained from parametric studies of varying eccentric moment and frequency, it can be seen that magnitude of maximum acceleration was proportional to the eccentric moment and square of frequency. It can also be seen that amplitude of displacement was roughly proportional to the eccentric moment but has nothing to do with the frequency. It can be said that all of the analysis results reflect characteristics of behavior of a pile in case of free vibration. Comparing the dynamic load transfer curves, maximum dynamic unit toe resistance was constant regardless of the eccentric moment and the frequency and it can be seen that dynamic unit skin friction was affected by the eccentric moment not by frequency. Comparing all of the analysis results, it can be said that the developed technique is reliable.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06a
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• pp.315-316
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• 2008

스냅샷은 파일 시스템의 손상 또는 사용자의 부주의로 인한 데이터 손실을 방지하기 위한 기술로 크게 볼륨 단위로 스냅샷 이미지를 생성하는 방법과 파일 단위로 스냅샷 이미지를 생성하는 방법으로 나뉜다. 첫 번째 방법은 현재 널리 사용되고 있는 방법으로 스냅샷 이미지를 생성하는데 걸리는 시간이 짧고 디스크 관리가 용이하다는 장점과 생성된 이미지의 개수와 파일 시스템의 I/O 성능이 반비례한다는 단점을 가지고 있다. 두 번째 방법은 다수의 스냅샷 이미지를 생성한 후에도 파일 시스템의 I/O 성능이 저하되지 않는다는 장점과 스냅샷 이미지를 생성하는데 걸리는 시간이 파일의 개수와 비례한다는 단점을 가지고 있다. 본 논문에서는 기존의 파일 시스템 단위의 스냅샷 기능이 가지는 단점을 극복하기 위한 Open ROW Snapshot에 대해서 언급한다.

• Annual Conference on Human and Language Technology
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• 2015.10a
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• pp.115-118
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• 2015

Neural Machine Translation (NMT) 모델은 단일 신경망 구조만을 사용하는 End-to-end 방식의 기계번역 모델로, 기존의 Statistical Machine Translation (SMT) 모델에 비해서 높은 성능을 보이고, Feature Engineering이 필요 없으며, 번역 모델 및 언어 모델의 역할을 단일 신경망에서 수행하여 디코더의 구조가 간단하다는 장점이 있다. 그러나 NMT 모델은 출력 언어 사전(Target Vocabulary)의 크기에 비례해서 학습 및 디코딩의 속도가 느려지기 때문에 출력 언어 사전의 크기에 제한을 갖는다는 단점이 있다. 본 논문에서는 NMT 모델의 출력 언어 사전의 크기 제한 문제를 해결하기 위해서, 입력 언어는 단어 단위로 읽고(Encoding) 출력 언어를 문자(Character) 단위로 생성(Decoding)하는 방법을 제안한다. 출력 언어를 문자 단위로 생성하게 되면 NMT 모델의 출력 언어 사전에 모든 문자를 포함할 수 있게 되어 출력 언어의 Out-of-vocabulary(OOV) 문제가 사라지고 출력 언어의 사전 크기가 줄어들어 학습 및 디코딩 속도가 빨라지게 된다. 실험 결과, 본 논문에서 제안한 방법이 영어-일본어 및 한국어-일본어 기계번역에서 기존의 단어 단위의 NMT 모델보다 우수한 성능을 보였다.

• School Mathematics
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• v.10 no.4
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• pp.603-623
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• 2008

The purpose of this research was to gain a better understanding of the characteristics of students' mathematical representations using additive strategy in ratio and proportion tasks. The additive strategy is the erroneous one used most often among the strategies reported in solving ratio and proportion tasks. It is a problem solving strategy that preserves the difference from one ratio to another. Students' additive strategies were categorized into four parts: subtracting without considering units of quantities, comparing the numbers that represent the whole subtracted from the part and same part, adding the difference, and subtracting the difference. In order to change from additive strategy to multiplicative strategy, the researcher asked to find out the unit quantity and found the characteristics of students' mathematical notations in the following: Firstly, the students made the number which they wanted by multiplying and adding same numbers. Secondly, they represented the mid-points between natural numbers. Thirdly, they related $a{\div}b$ to decimal number, not $\frac{a}{b}$. Fourthly, they were inclined to divide the larger number with the smaller number without understanding the context of the problem. These results are interpreted as showing that lower level of performance in the dividing operation with the notations of fraction hinders the transformation from additive strategy to multiplicative strategy.

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.3
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• pp.273-288
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• 2019

This study focuses on understanding proportionality, in particular, what constitutes relational understanding of a:b=c:d, which is called proportional expression. The meanings of a:b=c:d are analyzed and some suggestions are offered for improving the teaching and learning of it. The equation a:b=c:d has three different meanings. First, it represents two different structures in one proportional situation. Second, it represents a common structure in two different proportional situations. Finally, it represents a number or a quantity underlying in different proportional situations. It is important to choose and use a unit flexibly to understand the first and the second meanings of a:b=c:d, Double strip diagram and double number line are useful to visualize the meanings of a:b=c:d. In addition, what a number or a quantity in the third meaning of a:b=c:d refers to in proportional situations should be emphasized in teaching and learning of a:b=c:d.

• School Mathematics
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• v.14 no.1
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• pp.45-64
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• 2012

The purpose of the present study was to investigate middle grades (Grade 5-7) mathematics teachers' knowledge of partitive fraction division. The data were derived from a part of 40-hour professional development course on fractions, decimals, and proportions with 13 in-service teachers. In this study, I attempted to develop a model of teachers' way of knowing partitive fraction division in terms of two knowledge components: knowledge of units and partitioning operations. As a result, teachers' capacities to deal with a sharing division problem situation where the dividend and the divisor were relatively prime differed with regard to the two components. Teachers who reasoned with only two levels of units were limited in that the two-level structure they used did not show how much of one unit one person would get whereas teachers with three levels of units indicated more flexibilities in solving processes.